Mountain range that extends more than 1,860 mi (3,000 km) along the eastern margin of North America, from Alabama to Newfoundland. It was formed by the progressive eastward addition of material to the continental margin of North America. The earliest Appalachian sediments were deposited near the start of the Cambrian Period
Range of mountains in northwestern Europe, extending in a southwest-northeast direction from Ireland, Wales, and northern England through Norway. The mountains developed in the period from the start of the Cambrian Period (543 million years ago) to the end of the Silurian Period ( 417 million years ago). Remnants also exist in eastern Greenland